This invention relates to a controller and in particular to a liquid flow controller for intravenous injection.
It will be readily understood that the intravenous injection is an important medical method for those patients who are in a rather weak physical condition.
Commonly used apparatus for the intravenous injection, as shown in FIG. 9, mainly comprise a liquid bottle, a plug, a long P.V.C. tube, a pair of injectors and a adjustable flow controller. In assembling, a first injector passes through said plug disposed at the outlet of said liquid bottle which is filled with desired liquid and into said liquid bottle, and one end of said P.V.C. tube is connected to said first injector and the other end thereof is connected to a second injector, and a liquid flow controller is properly disposed on said P.V.C. tube and located between said first and second injectors. In operation the liquid will flow from the liquid bottle and through the first injector, the P.V.C. tube, the flow controller, the second injector and into the veins of the patients when one presses said P.V.C. tube. The liquid flow should be controlled by said flow controller according to the physical condition of each patient. However, according to the experience of those patients who have been injected via the veins, the controlling range of said conventional controller is somewhat limited and hence it is not suitable for patients who are extremely weak and need a slower flow rate of intravenous injection. Besides, according to the conventional way, the P.V.C. tube is directly pressed by the flow controller and hence said P.V.C. tube will easily become deformation, therefore it is difficult to obtain a desired flow rate by means of the conventional apparatus.
Accordingly, it is an object of the present invention to obviate the above-mentioned drawbacks.